Exemplary embodiments of the present disclosure relate to a gas turbine, and more particularly, to a system for cooling a gas turbine, which is capable of improving the efficiency of a gas turbine by individually supplying cooling air to each of a plurality of turbine disks included in a turbine disk unit so as to stably cool these expensive turbine disks.
In general, a gas turbine is a type of motor which jets combustion gas toward blades of a turbine to obtain torque, and may be largely configured of a compressor, a combustor, and a turbine. The compressor serves to compress air, which is introduced thereinto, to a high pressure by receiving a portion of power generated by the rotation of the turbine, and the compressed air is transferred to the combustor.
The combustor mixes and burns compressed air and fuel to generate the flow of high-temperature combustion gas, and then jets the combustion gas to the turbine, so that the turbine is rotated by the jetted combustion gas so as to obtain torque.
Here, each of the compressor and the turbine includes a plurality of turbine disks, each of which has blades radially coupled to the outer peripheral portion thereof. The compressor typically includes more turbine disks than that of the turbine. Hereinafter, a plurality of turbine disks arranged to the compressor is referred to as a “compressor section” and a plurality of turbine disks arranged to the turbine is referred to as a “turbine section”.
The individual turbine disks are fixed using a tie rod.
The tie rod is inserted to penetrate centers of the respective turbine disks, and the turbine disks may be fastened to each other by pressure nuts, which are coupled to both ends of the tie rod, so as not to be axially moved.
Meanwhile, since the combustor is arranged between the compressor section and the turbine section, the compressor section and the turbine section are spaced apart from each other such that a space for arrangement of the combustor is defined therebetween. Accordingly, the gas turbine additionally includes a torque transfer member which may transfer rotational torque generated by the turbine section to the compressor section.